To get a scoped rifle on the first mission, go to the barn where there is a lot of ammunition. Walk around, and you will be asked if you want to swap for the scoped rifle. Take the scoped rifle, and get all the ammunition desired. If you run out of ammunition, go back to the barn and get more. The ammunition is unlimited in the barn.

Achievements

Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Reporting for Duty (25 points): Kill 250 enemies.

More Than Enough (50 points): Kill 500 enemies.

Tough Guy (75 points): Kill 750 enemies.

Sprint to the Finish (20 points): Complete a mission below the target time.